Twitter with @AbuAbdallahF #3: Misconceptions about evolution
The main thing I want to do when talking about evolution is to point out how evolution actually works. First, though, I want to address the possible misconceptions @AbuAbdallahF has about this topic. This already contains a lot of information, but it is by no means exhaustive. Indented sections are quotes directly from him.
1. Evolution and the Origin of the Universe
You’re saying ‘No, there is no Creator, there is no purpose, it’s all random mutations’.
You’re claiming we are the result of random mutations over millions of years. But that still doesn’t explain how life began.
I am not sure what mutations have to do with creation myths. Let’s clear one thing up right off the bat: The theory of evolution by natural selection (Darwinism) makes no statements about the origins of the universe whatsoever. It doesn’t even try to explain the origin of life. It is simply the explanation of how organisms change over usually many generations.
2. Random Mutations and Natural Selection
Randomness? No purpose? Chance? Simply throw bricks randomly and millions of years later they will arrange themselves into a useful building? Sorry but that simply doesn’t make sense.
This is not how evolution works at all, if this is supposed to be an analogy.
When new life starts out building itself it is generally much smaller and looks much different than the final form it will take. For humans this first form is especially small: it is one cell. To reach its final form the organism needs information how to reproduce cells, what kind of cells are needed, and where they have to be placed. This information is encoded in genetic material. The actual molecular structure (DNA or mRNA) is irrelevant to the comprehension of the concept, so just think of genetic material as a long string of data. This string of data contains sections called genes which correspond to the traits an organism will have. Examples of such traits are eye color and other similarly obvious things, but they can also be subtle and sometimes ultimately inconsequential, like a higher risk for certain types of cancer, which might or might not lead to an effect. The specific version of the gene resulting in its specific version of the trait in question is called an allele. As an example of this distinction: every human has a gene for eye color, but it is the version of the gene, the allele, that determines whether it will result in brown or blue eye color. In colloquial language, the word gene is incorrectly used interchangeably with the word allele.
When random mutations happen in genetic material one or more of these alleles are changed into another. When this change happens in a cell that is passed on to the next generation (for example in the human zygote) this change will change one more traits the offspring will take, which may more may not influence the probability that this offspring itself will reproduce. There are three possibilities:
a) The change is neutral concerning reproduction rate and probability In this case, the offspring will reproduce at statistically the same rate as the “parent” with the “original” allele. Because it will reproduce with its kind, if it does, some of the children will carry the “old” allele, while some will carry the “new” one. A change has happened. An intuitive example for this could be eye color. An allele for brown eye color will not have an effect on the reproduction rate of a human when compared to a human with an allele for blue eye color. b) The change creates a disadvantage concerning reproduction rate and probability In this case, the allele is less likely to be passed on and if it is, the children suffer from the same disadvantage. Even if the change is not directly fatal, such traits usually die out over a few generations because populations exhibiting the “new” trait compete with populations carrying the “old” allele, or the new population is forced into other habitats. In some cases, the trait producing the disadvantage will only be effective in a small number of individuals carrying the allele, in which case the allele can be passed on. An example for this last case could be a disposition towards colon cancer. An example for a fatal change in a gene could be a missing head at birth; an example for a change that creates a disadvantage that would die out over time could be the disfigurement of limbs to the point of uselessness. c) The change creates an advantage concerning reproduction rate and probability In this case, the allele is more likely to be passed on to the next generation than the old one was. The situation is the same as in b), except reversed.
In summary, mutations that lead to advantages in reproduction also lead to propagation of that allele while mutations that lead to disadvantages are likely to disappear due to completely natural reasons. Over millions of years the accumulation of such smaller and larger changes leads to vastly different life forms.
3. Evolution’s Will
You told me that some random mutations will eventually (over millions of years) result in a better species increasing chance of survival. But death does not depend on health. Besides, like I said, if that is true, then let’s help evolution and randomly mutate every single animal on the planet and see what happens.
First of all, no, I did not tell him that. Evolution doesn’t in any way aim to create a life form with increased chances of survival. The mechanism simply abides by the law that things that procreate pass on their allele and things that don’t, don’t. Any change that just happens to decrease the chance of survival also decreases the chance of procreation, diminishing the probability that the corresponding allele is passed on.
Death does not depend on health? What’s that supposed to mean? I’m pretty sure a guy with terminal cancer has a higher chance of dying than someone without the condition, for example. That’s why it’s called “terminal”.
I don’t know what the last sentence is supposed to mean. We can’t mutate animals; the only thing that mutates in this context are genes.
4. Natural Processes and Perfect Bodies
Our bodies with their different systems, each system containing organs, each organ containing components…do you realize that we are machines controlled by information? We are much more sophisticated than any machine man has ever created. Even Dawkins admitted that biology has become study of information technology in the bodies of living things. And each bone, each system each muscle, each cell is placed in its’ well defined place in order to function properly. One single cell out of the many is more sophisticated than anything man has ever built.
Yet, this is exactly what you’d expect from a natural system where change occurs, “bad” changes naturally die off, “good” changes survive and lots of time passes. The information we are “controlled” by is our genetic material, which changes due to mutations.
Additionally, many of the traits that either were not relevant to our procreation probability or have outlived their “purpose” are still observable in our own bodies. He says our bodies are sophisticated because they were designed, yet we can easily conceive of a body that has much better properties. It would be nice to have an immune system that responds to more threats than it does, or no appendix that can suddenly rupture, or tissue that regenerates faster, or even limbs that grow back if lost. There is no technical reason why our bodies couldn’t be that way assuming a designer exists. So if there is a designer, it sure is an incompetent one. Except for the fact that a designer is completely superfluous; our genetic material instead evolved by natural processes, and the results just happen to be what they are.
5. But ... cancer?
You tell me it’s the result of random mutations…sorry man, that doesn’t make sense. Mutations do appear but they result in malfunction. In reality everything is decaying, everything is growing weaker and weaker because of mutations…diseases, like cancer or some other harmful mutations.
Mutations in genetic material that is passed on to the next generation that leads to malfunction doesn’t make it into the next generation, because beings that carry this genetic material die before they can procreate further. What he is probably talking about is an idea like cancer: a mutation in a cell in your body that leads to malicious procreation of cells. But cancer doesn’t get passed on to the next generation, and if it did, children of a person with cancer would likely not procreate as much as people without. It is important to understand that we are talking about differences between generations of an organism, not changes that occur in the body of one individual long after birth or, even further from the truth, in many individuals of the same organism simultaneously.
I fucking love science
Evolution is a fascinating topic on its own. Please be aware that many of the things I presented in this post are simplified and much more complex in reality. There’s much to be said how alleles influence traits of a life form. There’s a lot of interesting reading material about the mechanism by which DNA leads to these traits. There’s even more interesting material on the laws by which traits are chosen by the gene that governs them, which is one of the main things that was simplified in this post. The best place to start if this is interesting to anyone are Gregor Mendel’s experiments on pea hybridization in the middle of the 18th century which help you understand the concept of dominant and recessive alleles.
By far the most interesting book on genetics in my opinion is Richard Dawkins’ book “The selfish gene”. If after reading this book and honestly trying to understand what is explained in it someone can still say evolution is a hoax, I would forever be in awe of his or her willful ignorance. As always, send me critique on tumblr and twitter and I will see to correcting any misrepresentations as soon as I have confirmed them.